Protein C, Human Plasma

Protein C (PROC) is a vitamin K-dependent serine protease which regulates blood coagulation by inactivating factors Va and VIIIa in the presence of calcium ions and phospholipids. PROC is cleaved to its activated form by the thrombin-thrombomodulin complex. This activated form, which contains a serine protease domain, functions in degradation of the activated forms of coagulation factors V and VIII. Mutations in the PROC gene are linked with thrombophilia due to protein C deficiency, neonatal purpura fulminans, and recurrent venous thrombosis. This protein is purified from fresh frozen human plasma using a combination of salt precipitations and column chromatography.